fix(dao): page size 1 does not work for lmdb

Fix KAG-5875

.requirements

@@ -16,7 +16,7 @@ LIBEXPAT_SHA256=d4cf38d26e21a56654ffe4acd9cd5481164619626802328506a2869afab29ab3
 # Note: git repositories can be loaded from local path if path is set as value
 
 LUA_KONG_NGINX_MODULE=3eb89666f84348fa0599d4e0a29ccf89511e8b75 # 0.13.0
-LUA_RESTY_LMDB=890b3caf45bd052e319e48349ef393ec93e08ac4 # 1.5.0
+LUA_RESTY_LMDB=9da0e9f3313960d06e2d8e718b7ac494faa500f1 # 1.6.0
 LUA_RESTY_EVENTS=bc85295b7c23eda2dbf2b4acec35c93f77b26787 # 0.3.1
 LUA_RESTY_SIMDJSON=7e6466ce91b2bc763b45701a4f055e94b1e8143b # 1.1.0
 LUA_RESTY_WEBSOCKET=966c69c39f03029b9b42ec0f8e55aaed7d6eebc0 # 0.4.0.1

changelog/unreleased/kong/bump-lua-resty-lmdb-2.yml

@@ -0,0 +1,3 @@
+message: Bumped lua-resty-lmdb to 1.6.0. Allowing page_size to be 1.
+type: dependency
+scope: Core

kong/db/strategies/off/init.lua

@@ -120,10 +120,6 @@ local function page_for_prefix(self, prefix, size, offset, options, follow)
     size = self.connector:get_page_size(options)
   end
 
-  -- LMDB 'page_size' can not be less than 2
-  -- see: https://github.com/Kong/lua-resty-lmdb?tab=readme-ov-file#page
-  size = math.max(size, LMDB_MIN_PAGE_SIZE)
-
   offset = offset or prefix
 
   local res, err_or_more = lmdb_prefix.page(offset, prefix, nil, size)

spec/02-integration/04-admin_api/07-upstreams_routes_spec.lua

@@ -835,3 +835,64 @@ describe("Admin API: #" .. strategy, function()
 end)
 
 end
+
+for _, strategy in helpers.all_strategies() do
+  describe("#regression #" .. strategy, function()
+    local client
+    lazy_setup(function()
+      local bp, _ = helpers.get_db_utils(strategy)
+      bp.upstreams:insert {
+        name = "my-upstream",
+        slots = 100,
+      }
+      bp.upstreams:insert {
+        name = "my-upstream-2",
+        slots = 100,
+      }
+      bp.upstreams:insert {
+        name = "my-upstream-3",
+        slots = 100,
+      }
+
+      assert(helpers.start_kong{
+        database = strategy
+      })
+      client = assert(helpers.admin_client())
+    end)
+
+    lazy_teardown(function()
+      if client then client:close() end
+      helpers.stop_kong()
+    end)
+
+    it("page size 1", function()
+      local res = assert(client:send {
+        method = "GET",
+        path = "/upstreams?size=1"
+      })
+      assert.response(res).has.status(200)
+      local json = assert.response(res).has.jsonbody()
+      assert.equal(1, #json.data)
+      assert.truthy(json.offset)
+
+      res = assert(client:send {
+        method = "GET",
+        path = "/upstreams",
+        query = {size = 1, offset = json.offset}
+      })
+      assert.response(res).has.status(200)
+      local json = assert.response(res).has.jsonbody()
+      assert.equal(1, #json.data)
+      assert.truthy(json.offset)
+
+      res = assert(client:send {
+        method = "GET",
+        path = "/upstreams?size=2"
+      })
+      assert.response(res).has.status(200)
+      local json = assert.response(res).has.jsonbody()
+      assert.equal(2, #json.data)
+      assert.truthy(json.offset)
+    end)
+  end)
+end